#7531 Fix again for IE9RC. Enhances ajaxSetup so that it can take an optional target option, in which case target will be updated instead of ajaxSettings. That way, fields that shouldn’t be deep extended can be listed and dealt with in one place. jQuery.ajax now makes use of ajaxSetup with target to create its internal settings object

#8135 Makes sure any exception thrown by Firefox when trying to access an XMLHttpRequest property when a network error occured is caught and notified as an error. Added test/networkerror.html to test the behavior

#8138 Access to document.location is made only once at load time and if it fails (throwing an exception in IE when document.domain is already set), we use the href of an A element instead